And there's more. The film Hounddog has caused outrage by showing the rape of a 12-year-old child and the Deutsche Oper Berlin have pulled a production of Idomeneo which added a scene showing the severed head of the prophet Muhammad. Who the hell gives artists the right to offend people left, right and centre?

The answer is we do. And long may artists continue to offend and challenge us. At the heart of the argument over freedom of artistic expression is our ability to judge for ourselves and to discuss ideas in art and literature, whatever those ideas may be and however they are expressed. This was something grasped 50 years ago when the US judge Clayton Horn gave a landmark ruling in the obscenity trial of Allen Ginsberg's Howl. Clayton Horn was hardly a man with a liberal pedigree: he was a Bible school teacher who had gained a certain notoriety in San Francisco after he sentenced female shoplifters to watch de Mille's The Ten Commandments and write essays extolling the virtues they had gleaned from this masterpiece. But his 1957 written verdict stands the test of time:

'No two persons think alike ... would there be any freedom of press and speech if one must reduce his vocabulary to innocuous euphemism? An author should be real in treating his subject and be allowed to express his thoughts and ideas in his own words ... I have confidence in the ability of our people to reject noxious literature as I have in their capacity to sort out the true from the false in theology, economics, politics or any other field'.

What the judge understood is that freedom of ideas is part and parcel not only of artistic expression but also of a free society. The bitter irony confronting us today is that an apparent reactionary such as Clayton Horn is a hero compared to many today who deem themselves politically progressive but are in fact the new inquisitors of art and culture.

Censorship has changed. Censors are no longer concerned with the idea that literature and art may corrupt or deprave the masses. Instead, the arts are operating under the slow thumbscrew of self-appointed inquisitors who claim they are speaking for and protecting the interests of the vulnerable.

What is happening in arts censorship today is difficult to grasp and seldom confronted because often the censorship comes from within. Arts organisations are censoring themselves to avoid causing offence. Tate Britain's decision to remove John Latham's God Is Great from an exhibition of his work because it featured a Koran embedded in glass is one of the more high profile examples of this, but self-censorship is far more pernicious and far-reaching.

Arts Council funding applications, with their questions on inclusivity and racial demographics, operate as a de facto pre-publication, pre-production censor for many cash-strapped arts organisations - reviving a practice we abandoned along with the Licensing Act in 1695 as an anathema to a free and creative society. We need to start celebrating art for art's sake and trust ourselves to debate art and politics with no regard for each other's culture or background. We're adults. We can handle it.